With development of science and technology, a variety of display devices have been gradually applied in people's daily life and work, and have provided great convenience for people's daily life and work.
A transparent display device is a new display device by which image may be displayed and through which the environment behind the transparent display device can be seen.
However, since the conventional transparent display device is transparent, contrast of the image displayed on the conventional transparent display device may be greatly affected by the environment behind the transparent display device. The conventional transparent display device is provided with only a transparent display mode, and a light transmission state is not adjustable.